Oil burner



May 11 1926.

T. DAVIS OIL BURNER Filed May 8 1923 FIELI.

5 Sh eets-Sheet 1 INVEN T0 R. Tray 00 v/s 21 ATTORNEYS.

T. DAVIS OIL BURNER May 11 1926.

Filed May 8 1923 5 Sheets-Sheet 2 INVENTOR.

4Q ATTORNEYS.

WITNESS.

May 11 1926. 1,584,617

- T. DAVIS OIL BURNER Filed May 8 1923 5 Sheets-Sheet. 5

INVEN TO R. 770 001 75 WITNESS m BY I ATTORNEYS.

May 11,1926. 1,584,617

, T. DAVIS OIL BURNER Filed May 8 1923 5 Sheets-Sheet 4 28 I 0*:F|E1.lU. 4 'w '2 l3 5 I2? INVENTOR. 7 77-06 0014's. WITNESS mflaf/iw/ATTORNEYS.

May 11 1926.

T. DAVIS OIL BURNER Filed May 8 1923 III In F 5 Sheets-Sheet 5 II /N VEN70!? 770 gal/4.5

Patented May ll, 19%.

teeter that rates.

TRAY DAVIS. OF BERKELEY, CALIFORNIA, ASSIGNOR T0 BUNTING IRON WORKS, OF

SAN FRANCISCO, CALIFORNIA, A CORPORATION OF CALIFORNIA.

OIL Brianna.

' Application filed May 8, 1923. Serial No. 637,434.

This invention relates to liquid fuel burners, and more particularlyto'an oil burner that is arranged to be supported on the outside wall ofa combustion chamber and to be moved into proper position, with thenozzle extending into the chamber. Oil burners of this generalconstruction are now wellknown, and are extensively used for exto theregulation of the ample in the generation of steam for use in powerplants or in house heating plants.

There are usually correlated with the burner itself a pump for supplyingthe liquid fuel to the nozzle, as well as a fan for assisting theformation of a fuel spray.

" To insure against an accumulatlon of unused fuel, it is customary toprovide for a fuel return. It is one of the objects of my invention toprovide a fuel supply and return system of simple and inexpensiveconstruction.

It is another object of my invention to improve in general theconstruction of oil burners of this type.

In order that the liquid fuel be completely burned in the combustionchamber, sufficient air must be introduced for this purpose; Ifexcessive air is introduced, however, the result is objectionablebecause of the absorption of heat thereby. Another element that shouldbe varied with the rate or burning is the rate at which air is suppliedfor atomizing and projectingthe fuel spray. It is another object of myinvention to "provide for a regulation of these features in responsefuel fed to the device.

It is still another pb-ject of my invention to support the entire oilburner in a manner that Wlll readily permit the combustion chamber to becleaned. This I accomplish by providing a comparatively large-Sizedhinged door for the combustion chamber, on which door in turn is hingedthe oil burner. Thus when it is desired merely to inspect the burner orthe combustion cham ber, or to start the burner operation, the largedoor is left closed, and the burner alone is swung out of the combustionchamber on its pivots on the door. If it should be necessary to repairor clean the combustion chamber, the hinged door is moved so as toexpose a comparatively large opening.

Oil burners usually employ a draft of air to project the spray of fuelfrom the edge of a rotating cup. This cup throws ed the atomized fuel bycentrifugal force, and the draft of air is intended to direct this fuelto the interior of the combustion chamber. It is another object of myinvention so to direct this air draft that less power for driving theair will be needed for accomplishing this result satisfactorily.

My invention possesses other advantageous-features, some of which Withthe foregoing willbe set forth at length in the following description,where I shall outline 1n full that form of the invention which I haveselected for illustration in the drawings accompanyingand forming partof the present specification. Although I have shown but one embodimentof my invention in the drawings, it is to be understood that.

the 011 burner shown in Fig. 1, but installed on a furnace wall; 4

Fig. 3 is a front view of the burner shown in Fig. 2, with some of theparts broken away and others in section, so that the construction may bemore clearly indicated;

Fi 4 is a fragmentary elevational view, showing the fuel valve and-itsassociated parts, used on the oil burner of Figs. 1 and 2;

Fig. 5 is a sectional view along the plane 55 of Fig.4;

I Fig. 6 is a perspective view of the fuel inlet controlling device,used in connection with the fuel valve of Figs. 4 and 5;

Fig. 7 is a sectional view along plane 77 of Fig. 3;

Fig. 8 is a sectional view along 8-8 of Fig. 3;

Fig. 9 is a fragmentary view of one form of the invention, in which anopening in the combustion chamberthrough which the oil nozzle is adaptedto extend is formed by a stationary member, instead of by a door asindicated in Fig. ,1; and

plane Fig. 10 is a fragmentary sectional view stallation utilizing anoil burner of my i11- vention, is shown in Fig. 1. In this arrangementthe boiler is shown as arranged above a combustion chamber 86. The oilburner 87 is supported externally of the chamber 86, although its fuelburning parts extend through one of the walls of chamber 86, where theyserve to burn the fuel and produce a temperature capable of operatingthe boiler 85. The external arrangement of all of the control parts ofthe burner 87 renders it capable of ready control, as by the aid of apressure governor 88, indicated merely diagrammatically in Fig. 1. Inorder that the mode of control may be well understood, it is first ofall necessary to describe the construction of the oil burner parts morein detail. For this purpose the succeeding figures have been provided onthe drawings.

I show, in Fig. 2, an oil cup 11 which may be of conical form, and whichextends through an opening in the wall 12 of the combustion chamber 86.This oil cup or nozzle 11 is preferably rotatable, and for this purposeit is appropriately fastened to a rotating shaft 13, as by aid of thethreaded extension 14, which engages a tapped hole in an intermediatewall 15 of the cup 11. This wall is pierced by a plurality of apertures16, for permitting oil to flow to the enlarged end of the cup 11. As iswell understood, the rotation of the cup 11 causes centrifugal force tothrow off the oil in a spray at the large end of the cup. In order torestrict this spray of oil into a comparatively narrow path, as well asto assist in the formation of the spray, a draft of air is directed pastthe outer end of the cup 11, betweena nozzle 17 surrounding the cup 11,and the outer surface of a deflector 128. The interior surface of nozzle17 is formed to provide an annular passageway for the i air draft, incombination with the annularly arranged deflector 128. This deflectormay be supported around the cup 11 by the aid of a plurality of bossesor projections 123 which are formed integral with the external activesurface of the deflector and serve to space it from the interior of thenozzle 17. The annular passageway 124 formed between the nozzle 17 andthe deflector 128 is directed inwardly toward the axis of the cup, andthe air blown therethrough is caused to converge thereto. The directionof this blast is of great importance, since it prevents the flaring outof the fuel spray from the edge of cup 11 under the influence ofcentrifugal force, without the necessity of a powerful air blast. Fromanother aspect, the inward direction of the air blast causes it in somemeasure -to neutralize the centrifugal force of the spray; and lessforce is required in an axial direction to prevent depositionof'unconsurned fuel on the wall 12 of the combustion chamber. Thiscentrifugal force is of course useful only for spraying or atomizing thefuel, and after the spraying is accomplished, it is desirable tominimize its effects as much as possible.

The particular details of the nozzle 17 may be varied somewhat whilestill using it for directing an inward blast of air. For example,another form of nozzle is illustrated in Fig. 10 for accomplishing thisresult. In this instance the nozzle is formed with an integral battle126 for directing the air to the high part of nozzle 125. From there theair escapes through a series of drilled apertures 127 directed inwardlytoward the axis of cup 11, and past its outer edge.

The draft of air conducted by either of nozzles 17 or 125 past the edgeof cup 11 may be conveniently produced by a fan 18, which is preferablyrotated by the shaft 13 which rotates the cup 11. The fan 18 is of thecentrifugal type, and may comprise a spider 15) keyed to an enlargedportion 20 of shaft 13. This spider has a hollow hub 89 to which areattached the spaced fan forming discs 21. Between the discs there may beradial partitions for driving oil the air, constructed and arranged inany well understood manner.

To provide appropriate passages for the air driven oll between the discs21, into the nozzle-like member 17, the fan is encased in a casingformed in this instance of a front casing member 22 and a rear casingmember 23, which when fastened together form a substantially tightchamber for the fan 18. These members 22 and 23 may be conveniently madeof castings, and may be fastened together by the aid of bolts 21 passingthrough lugs 25 cast integral with the casing members 22, 23. The fancasing forms in addition the support for a large part of the burnerstructure. Thus on the rear member 23 a boss 26 is provided for thehollow tube 27, which is adapted to support the nozzle 17, as by the aidof interengaging screw threads 28. A tapered aperture 29 through therear casing member 23 connects with the interior of the tube 27 and thenozzle l7, and in this way a continuous, gradually decreasing airpassage is obtained from the interior of the fan casing to the outer endof the oil cup 11. In order further to guide the air pro erly from thefan, radial ribs 122 may he formed on the rear easing member 23. For theair intake, the front casing member 22 is provided with an aperture 30,shown in this instance as axial, which connects the interior of casing25 with the external atmosphere, by way of the hollow hub 89 of spider19. The air supplied by the fan 18 for best results should be varied inaccordance with the intensity of combustion, so

that as more fuel is used, more air is supplied by the fan. This isessential in order to produce complete combustion without excess air atall times, and also to project ,the oil spray. In order that this airsupxply may be readily controlled, a shutter 90 is provided for theairinlet 30, which shut-- ter is shown as rotatable in a guide 91.

This guide has appropriate openings 92 therein \VlllCh are adapted to beclosed more 01' less by the shutter 90. This shutter arrangement isshown in the present instance as concentric to the shaft 13, as well asto the hub 89 ofspider 19. In order to move the shutter 90 a weightedlever arm 93 is provided, attached in any appropriatemanner to theshutter, and capable of movement in a circle around the axis of theshutter.

The shaft 13, which drives the fan 18 and the cup 11, is arranged to bedriven.

by anyappropriate source, such as a small electric motor 31. This motormay be conveniently carried on a bracket 32 fastened to the front of fancasing 25. A pump 33 for the fuel may also be supported on this bracketin a position convenient for' connection to the shaft 13, so that ittoomay be driven by the same source of power as the fan 18 and cup 11-Since the particular details of the motor 31 and of the pump form no.part of my present invention, I shall not describe these parts indetail. It is sufficient for the present purpose to ,specif that thepump ma convenientl' y y y be of the type that utilizes intermeshinggears for forcing the liquid into the supply pipe system of the oilburner.

To ermit the oil burner to be removed from the furnace so as to exposethe cup 11, the entire fan casing 22-23 is pivoted at one side of thecombustion chamber opening. As shown most clearlyin Fig.1, the

K fan casing 22 is pivotally supported on a swinging door 94, in whichan opening may be provided for permitting the cup 11 to project withinthe co mbustion chamber 86.

In Figs. 2 and 3 a slightly differentform of wall opening is shown-,inwhich the door 94 is omitted, but instead a frame 34, permanentlyattached to the combustion chamber opening, is shown. However, in eachform the opening which permits entry of the oil burner cup 11 into thecombustion chamber 86, is the same, and therefore at this point, onlythat form of the combustion chamber opening, illustrated in Figs. 2 and3, will be described. The door frame 34 illustrated in Figs. 2 and 3, isshown in greater detail ins Fig. 9. This door frame in the presentinstance has a rectangular opening 35, through which the oil nozzleparts may extend as shown in Fig. 2. The frame is appropriately fastenedto the wall 12 of the combustion chamber, as by the 7 aid of bolts 36..-The aperture 35 in the door frame registers with a correspondingaperture in the wall 12. Furthermore, to strengthen the door framecasting to a sufficient degree, and to form a guide to the brick masonin laying the bricks of the furnace wall, vanes or ribs '37 areprovided, one on each side of the aperture 35, which ribs extend for asubstantial distance into the aperture in wall 12. Other shallower ribssuch as 38 may also be provided on the back of the door frame 34. Thelugs 39 are located t-othe right of this frame, upon which lugs the fancasing 2223is pivoted. As shown in Fig. 3, the fan casing is providedwith corresponding hinge lugs \40, and each pair of lugs is providedwith a pivot pin 41, which extends almost entirely through both lugs ofeach pair.

In order to hold the entire fan casing 22-23 and its associated parts inproper closed position, a latch 42 is used, which is pivoted to lugs 43on the door frame 34. This latch has a. sloping face 44 which is engagedby the casing 22 as it is shut. An abrupt face 45 drops back of the fancasing as soon as this casing reaches its closedposition.- This closedposition is determined by the spacers 81 cast on the rear face of casingmember 23, which serve to maintain an air space between this member andthe wall 12. To urge the latch 42 to closed position, a compressionspring 46 is provided, which is guided by the bosses 47, 48 respectivelyon the door frame 34 and the latch 42. Fur thermore, a stop 95 on thelatch prevents it frombeing 'urgedtoo far by the spring 46.

The pump 33 is directly connected to the motor shaft and thus rotatestherewith. The

amount of oil delivered to-the burner nozzle is regulated by operationof a valve such as 59, interposedbetween the pump and the nozzle. Sincethe amount of oil delivered to the nozzle is variable and the speed ofthe pump is usually constant or is incapable of variation with the samedegree of fineness as the oil flow, the arrangement is purposely madesuch that an excess of oil is discharged by the pump, so that even forthe maximum demand, sufficient oil may be pro- Then excess oil iscaused" to flow therefore that two pipes, the, supply pipe and thereturn pipe, extend from the source of supply to the pump, providing'two..conduits, the continuity of which should not 'be interrupted bymovement of the burner structure in and out of the combustion chamber86. Ithas been customary to pass these two pipes through the hinges ofthe burner structure, using the pipes as hinge pins and providingrotatable connections on the pipes on the burner structure side of thehinge, so that the structure can be swung on the hinges withoutinterrupting the continuity of the pipes. In such a construction,'thesupply and return pipes are usually disposed at right angles to thehinge axis, and the plumber, in connecting these pipes to the conduithinge pin, frequently takes up too much on the pipes and springs thehinge, so that it does not function properly. This improper installationis very apt to result in leaks in the suction pipe, and the dischargepipe. Since the suction pipe must be maintained air tight in order tosupply oil to the burner, it becomes readily apparent howdisadvantagemts such a construction may become. Leaks'in the dischargepipe also are obiectiomtble because they augment the loss of oil andbesides produce disagreeable unsightly conditions in the neighborhood ofthe hinges. It is my object to teach how the ctmstruction may be changedso as to overcome these and other objections. In accord ance with myconstruction, the conduits do not pass through the hinges and areclan'iped to the blower casing so that they cannot be pulled out ofline. As shown most clearly in Figs. 3 and 8, I may employ a stationarypipe fitting 95, the main axis of which is preferably substantiallycoincident with that of the pins 4]. A lower axial passage in thisfitting 05 comnuinicatcs with a radial passage 50, and is used in'thisinstance to feed oil to the suction side of pump 33. For this purpose afeed pipe 51 is appropriately fastened, as by screw threads, into thepassage 50. An otfset pipe fitting 52 is rotatably mounted on the lowerextremity of the fitting 95'; in order to permit rotation withoutleakage a packing 53 is used, held around fitting 95 by the aid of ahexagonal union nut 54 engaging the threaded external periphery of theoffset 52. By the aid of this construction, the swinging of the fancasing 22 toand from the wall opening merely causes a correspondingswinging movement of the offset 52 with respect to the stationaryfitting 95.

From the outer end 55 ofthe offset 52, appropriate piping 56 is providedfor connecting the ofl'set to the intake 96 of pump 33. From thedischarge end 57 of this pump, there are two paths for the oil throughthe biased valve structure 58 back to the oil tank or reservoir, orthrough a hand-operated valve 50 to the oil burner cup 11. The biasedvalve structure 58 and the return are provided to reconduct all theunused oil to the tank, and these elements operate automatically uponthe production of a sufficient degree of pressure at the discharge end57 oi the pump 33. The biased valve 58 may be of any well knownconstruction; for example it may utilize a compression spring 60 to urgevalve 01 upon its seat (32. After the oil gets beyond this valve, itflows through piping 63 to an offset 64: en-

tirely similar to the ofiset 52 already described. This ofiset islikewise rotatably supported upon the upper end of the stationaryfitting 05, and is in communication with the axial opening 65. Thisopening in turn communicates with the radial opening 60, into which apipe 67 is threaded for returning the oil to the tank or reservoir.

In order to prevent the stationary fitting 05 from buckling in responseto a stress upon the pipes 51 and GT, straps 68 are provided, castintegral with the fan casing 92, and embracing the fitting 0.3 on eachside of the point where the pipes 51 and (ST enter. There is a cap 60tor each strap (38. The arrangement is such that relative rotativemovement between these straps and the litting 05 is possible.

The oil which is to be burned at the nozzle flows through the manualcontrol valve 50, The details of the hand controlled valve 50 and of itsassociated parts are most clearly illustrated in Figs. 4, 5 and (5. Inthese. figures the valve structure is shown as cast integral with thebiased valve 58; this combined structure is very compact. The manualcontrol is preferably supplemented by a, control responsive to theboiler conditions. as for instance by the pressure governor 88 ofFig. 1. For this purpose a hollow valve sleeve 97 is rotatably supportedwithin the valve structure 59, in such a way that its axis intersectsthat of the valve port 71. The opening of this valve port is controlledby the handle 98, but; the oil before it can proceed further must alsopass through the sleeve 97, in 'which a triangular opening 90 isprovided for this purpose. This triangular opening is located at such apoint, on the sleeves that it cooperates with the side walls of port 71to control the extent of the opening between the port 71 and theinterior of the tube 07. Thus by rotating the sleeve 97 by a limitedamount, the port opening may be varied. This rotation is effected by theaid of a stem 100 which is journaled in the valve structure 5.) andwhich has an extending squared portion 101. A packing nut 102 preventsleakage of oil past the bearing of this stem 100. Attached to thesquared )ortion 101 is an operating lever 106 which has an extension 103operating between the limiting stops 10 1. Thesestops are formed by 'capScrews adjustable in lugs 105 on the valve structure 59,- and serve tolimit the rotation of sleeve 97.

The lever 106 has another extension 107 which serves for theattachn'ient of the weighted operating rod 108, shown most clearly inFig. 1. This rod is connected mechanically to the pressure governor 88,by any appropriate device, such as a chain or wire 109. The arrangementis such that the supply of oil is so controlled by this pressuregovernor and elements 108, 106, and 97, that a constant predeterminedpressure is maintained. In other words, upon an "excessive increase inpressure, the rod 108 is rotated in such a direction as to decrease theoil opening, while a decrease in pressure will cause the oil opening toincrease in extent. I also, prefer to control simultaneously the openingof-the hinged damper door 111 at the bottom of the combustion chamber.For this purpose a connection 112 is provided between the door 111 andany appropriate portion'of the control mechanism, as for example, to thelever 108. Simultaneously with this control, the air intake to fan 18 iscontrolled by the aid of a connection 110 between the governor 88 andthe shutter lever 93. The amount of air delivered both by the fan andthrough the door 111 is proportioned properly to the rate of combustionof the oil, so that there is just sufficient air introduced to cause.complote combustion. JVhile of course this effect could be obtained bysimply controlling either the opening of door 111 or the air intake tofan 18, I prefer to accomplish this by a combined'control as shown, sothat the control of the fan intake may serve also to control the speedof projection of the oil by the fan blast from the cup 11.

After the fuel passes into tube 97 by way of the opening 99, it'ispermitted to flow through an elbow 113 (Figs. 2 and 5) fastened to thevalve structure 59 so that one of its arms is alined with the hollowtube 97. Into this elbow extends-a supply tube 72, preferably made ofcopper. This tube 72 extends downwardly, as shown in Fig. 2, and thenradially back of the rear casing member 23, as shown most clearly inFig. 3. It then extends through the aperture 35, the wall of which iscut away to forma lip 73 of conical form, with its axis extending upwardand. to the rear. This lip is shown most clearly in Fig. 9. Finally thepipe 72 enters the tube 27, which has an integral interior boss 74joined to the wall of the tube by an extension 75. Through thisextension an aperture 76 is provided, which serves to place the pipe 72in communication with an oil tube 77. This tube may be appropriatelyanchored in the boss 74, and as shown in Fig. 2 it extends into the oilcup 11, so that oil coming through this pipe is forced through theapertures 16 in the wall 15. Contact between the oil and shaft 13 isprevented by a tube 78 serving as a hood and held concentrically withtube 77 inside of boss 74 so as to extend coaxially with. the oil tube 77. Since the tube 78 fits tightly in an aperture 79 in boss 74, andsince the oil tube 77 fits tightly in a counter bore 80 for thisaperture, it is evident that the flow of oil from pipe 72 is confined toan annular chamber formed between the two tubes 77 and 78. r y

In Fig. 9 a permanently fastened frame 34 is shown, on which the oilburner 87 may be swung. Such a permanently attached frame is not anessential feature, since this frame itself may be pivoted and form adoor. Such an alternative form is shown in Fig. 1, wherein the hingeddoor 94 replaces the construction shown in Fig. 9. This door 94 is swungon pivots 114. In order that the door 94 may be-swung withoutinterfering with the oil supply to the burner 87, a pipe construction115 isprovided which has parts swinging on an axis substantiallycoinciding with that of the pivots 114. This pipe construction 115 isentirely similar to that described previously in connection with theswinging of the burner 87, and for that rea: son it is not consideredessential to describe this element in any greater detail. Sufiiee it tosay that the supply and return pipes 51 and 67 connect to a pipe fitting116 which may be rotated about its axis relative to the stationaryfittings 117 and 118. These fittings connect respectively to the supplypipe 119 and the return pipe 120., Should the necessity ever arise forgaining access to the interior of the combustion chamber, a largeopening thereto is readily available. Furthermore,-tl1ere is no need forproviding supplementary openings to the 'fuel chamber, as is common inother tion.

A pressure gauge 121 may be used in connection with the valve structure59 to indicate the oil pressure produced therein by the pump 33.

I claim! 1. In an oil burner, a pivoted door, means for pivotallysupporting the oil burner on the door, a stationary pipe, meansrotatable relatively to the pipe and connecting therewith for conductingoil, the rotation being on'the axis of movement of the door, andcoincident therewith, and means leading from the rotatable means to theoil burner for supplying oil thereto.

2. In an oil burner, a pivoted door, an

oil burner pivotally supported on the door in such a way that itprojects through an aperture in the door, and means for supplying oil tothe burner, com rising a pairo re atively rotatable pipe ttings arrangedwith the axis of rotation coincident with that of the door, and anotherpair of relatively rotatable pipe fittings arranged'with the axis ofrotation coincident with that of the burner.

In testimony whereof, I have hereunto set types of installa-

